The front and back are mat board covered with a lovely hand-made paper with leaf inclusions that I found, at all places, in Office Depot. (Yes, they are all over Mexico.) Instead of a spine, there are two leather "hinges" stitched to the front and back. The stitching, a variation of the longstitch binding, is done over the leather hinge straps.
When I do this book again, I'll make a few changes in the way the ends are stitched. The other problem with it is that it really does not want to lie flat when closed. I have fussed with getting the stitching centered on the leather straps and it helps. Perhaps, like yesterday's cracker box book (which is now beautifully flat), all it needs is a few hours under weights. I'll try that.
The book has 10 signatures of 6 sheets each, making 120 book leaves, 240 pages both sides, of hand-torn text-weight paper. Stitching is with waxed linen thread.